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Seattle is now several steps closer to having wild landscape on a 500-acre park within city limits. At Discovery Park, the natural environment is being reclaimed and reestablished on areas previously developed through logging, farming, and military base development.
This much-loved but overused land has become a fragile ecosystem at risk. In an effort to enhance and stabilize existing habitats, introduce new habitat, limit the expansion of invasive species, and provide for compatible human use, the City of Seattle has earmarked $1.1 million for the Discovery Park Habitat Improvement Project. As a result, 50 acres of Discovery Park will benefit by habitat improvements.
The project team set out to bring the park ecosystems closer to a self-sustaining wild environment, while coupling capital improvements with a parks maintenance plan. Led Swift & Company Landscape Architects and project manager Kevin Stoops, the team included park maintenance staff, native plant specialists, biologists, hydrologists, geotechnical engineers and urban foresters.
Following the evaluation of existing ecosystems, use patterns and maintenance limitations, participants identified critical environmental improvements using landscape ecology and systems evaluation methods. Each restoration or reclamation activity was designed to enhance species diversity and habitat opportunities and guided by knowledge of Puget Sound lowland successional ecosystems.
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| One of Discovery Park's major ecosystems, Puget Sound lowland forest. |
All improvements were refined fit projected maintenance capabilities. Forestry and farming methods were used to develop practical, cost effective solutions.
At the center of the project was the need to upgrade soils and build nutrient sinks to support existing and new plant communities over the next ten years. The existing nutrient-deficient soils have placed the park at constant risk to invasive species like Scot's Broom.
A biosolid demonstration project has been implemented in 14 acres of Discovery Park's south meadow to upgrade soils. The King County Department of Metropolitan Services has donated and applied biosolids from the nearby West Point Sewage Treatment Plant, thereby bringing an additional quarter-million dollars of improvements to the park. Considerable coordination and research was required by the project manager and landscape architects to obtain a health permit for the demonstration project and to acquire acceptance by the public. All other project areas in the park received a substantial organic soil amendment derived from composted biosolids and recycled yard waste.
The planting strategy for the habitat improvement project is to build upon existing conditions to connect and expand plant communities, creating the edge conditions and interior patches so vital to good animal habitat. Invasive, introduced species such as Scot's broom were identified for removal and control, while other non-invasive species were left to continue as part of the landscape matrix.
An inventory of existing native plant growth provided information about site conditions and became the basis for species composition in the new planting areas. New plant grouping typically include multiple sizes of bareroot trees, shrubs and herbaceous plants densely and randomly spaced in drifts to replicate the natural occurrence at similar sites. In the south meadow, where the exposed land form is buffeted by wind and rain, new plantings were located on the lee side of existing plant masses in anticipation of natural migratory patterns. Over a ton of native tree, shrub and herb seeds have been hydroseeded to encourage a succession of plant communities. Importing a seed bank of the appropriate plant combination for a given site was a cost effective, long-term method of establishing plantings. Natural selection will eventually refine the mix of plants at the site. Some of the seeds were actually collected from the park during native seed collection workshop cosponsored by the Parks Department and Swift & Company. Over 35 pounds of seed were collected by enthusiastic volunteers who learned harvesting and processing techniques.
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| Discovery Park's South Meadow offers dramatic views of the Puget Sound and Olympic Mountains. |
The provision of new habitats in the park focused on water and it's central role determining the range and type of habitats in the park. A review of the major watersheds uncovered the opportunity to daylight clean storm water in an open vernal pond to the north of the meadows. The 52,000-square-foot pond drains into a forested area where dilapidated maintenance buildings and hazardous waste from underground storage tanks were removed and replaced by a new wet forest. The removal of the old maintenance facilities continues the slow effort to return developed portions of the former military base to a natural environment. Further to the north, a small existing wetland was enlarged to include a forested pool with visitor access.
Even wild places set aside for human use in an urban environment need to be accessible.
To meet visitor needs in the south part of the park, improvements included an upgraded entrance to the park and an expanded parking lot. A new trail from the parking lot to a stonewall viewpoint was built to offer an accessible picnic area with a glorious meadow and Puget Sound views. An interpretive display will be installed to introduce the visitor to the ecosystems in the park. Near the north parking lot, the expanded wetland was designed with an accessible trail for environmental education programs for school children and day camp students.
As part of providing for human access to a wild place is helping visitors understand their role as users. The project objectives were discussed in public meetings, the seed collection workshop and site signage installed during construction explained the habitat improvement efforts.
As the construction effort comes to a close this spring, visitors will see new plant communities leaf out, a vernal pool fill, and new grasslands provide nesting sites for small birds and mammals. Over the next few years, the plant protection fences and temporary irrigation will be removed and the wild character of Discovery Park will offer visitors the experience of sweeping meadows with spectacular views of water and mountains, maturing second-growth forests which are home to bald eagles, eroding bluffs, and sandy beaches.
Barbara Swift is principal of Swift & Company Landscape Architects, primary consultant for the design of Discovery Park Habitat Improvements. Subconsultants include:
The general contractor is Ohno Construction Inc.
The project manager for the City of Seattle Department of Parks and Recreation is Kevin Stoops.
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